Small vascular channels often develop within previously obstructed arteries, but usually such channels are quite small and the arterial lumen consequently remains quite narrowed. That large channels consisting of muscular arteries and capable of carrying sizable quantities of blood may develop in previously obstructed larger muscular arteries is not a well recognized observation. Such was the case in 2 patients described in this paper. Each patient in the report had healed transmural left ventricular scars and severe narrowing of 1 major epicardial coronary artery without any narrowing of the other major arteries. Numerous small muscular arteries had formed in the narrowed lumens of a previously obstructed artery. Patient #1 had an embolus to the left anterior descending coronary artery during active infective endocarditis involving the aortic valve and the embolic material subsequently organized to form the new small muscular arteries within the larger muscular artery. Patient #2 presumably also had thrombus or embolus in the ramus branch of the left main coronary artery but its source was not determined; it too subsequently organized with development of multiple new muscular arteries within the obstructed artery. These 2 patients demonstrate that the human body is capable of forming normal coronary arteries within large epicardial coronary arteries. Had coronary angiogram been performed in each of these 2 patients after healing of the acute myocardial infarction almost surely the artery containing the newly formed arteries within the previously obstructed artery would have appeared angiographically normal. Thus, formation of multiple new small muscular arteries within previously obstructed large muscular coronary arteries is a mechanism of producing angiographically normal coronary arteries after healing of acute myocardial infarction.